Agree with you on the need to explore this further especially if an article is clogged with very bad photos. But after arguing for so long against the automatic removal of negative photos, the benchmark got to be set very high. My only concern however is once a point is set, it becomes easy fodder for point grabber to take advantage to win some points.

An alternative perhaps might be for the administrators to monitor user activity of owners of highly negative photos. Say if a photo reaches -xx and the user has been inactive for Y months, an email can be sent. After a further Z months, with continued non user activity, then the photo should be removed.